If (x + 1/x)^2 = 98, compute x^2 + 1/x^2.
GATE 2014 · General Aptitude · Numerical Computation · easy
Answer: x^2 + 1/x^2 = 96
- Expand (x + 1/x)^2: (x + 1/x)^2 = x^2 + 2 + 1/x^2. Since (x + 1/x)^2 = 98, we have x^2 + 2 + 1/x^2 = 98.
- Solve for x^2 + 1/x^2: x^2 + 1/x^2 = 98 - 2 = 96.